A New High Performance Detector for Small Animal SPECT

描述(由申请人提供)：在各种功能成像技术中，SPECT在小动物疾病模型的研究以及患者护理中保持着重要的作用。许多SPECT标记的成像探针具有很高的特异性分布，背景很少，正被用于测量小动物的一系列重要生物参数，包括底物代谢、血流、低氧、蛋白质合成和受体特性。近年来，随着体内转基因表达成像方法的发展，这一重要手段的实用性已显著增强。此外，SPECT能够通过一项成像研究来关联两个生物过程的双同位素成像。最近对小动物SPECT的需求也受到制药行业的推动，在该行业中，有必要对生物过程进行活体量化，以衡量试剂的作用机制及其在作用部位的浓度。这些应用中的每一个都需要出色的空间分辨率，这不仅是因为要成像的细节的规模很小，而且还因为对检测和估计任务的要求很高。遗憾的是，现有的SPECT仪器不能提供所需的性能，因此高分辨率探测器的开发对于未来SPECT系统的改进至关重要。为了解决这些问题，我们建议开发一种基于闪烁体的独特设计的新型探测器，该闪烁体与非常高的空间分辨率读出相耦合。具体地说，闪烁体的设计和制造将使由于闪烁体内的相互作用深度效应引起的视差误差引起的分辨率损失最小化，同时保持非常高的入射辐射检测效率。这种闪烁体和读出器的组合，当与定制设计的准直器相结合时，将形成一个SPECT探测器模块，可以以经济高效的方式实现极高的空间分辨率和高灵敏度。探测器模块成功开发之后的工作将侧重于开发一个完整的小动物SPECT系统作为原型产品。

DESCRIPTION (provided by applicant): Among the various functional imaging techniques, SPECT maintains an important role in the study of disease models in small animals as well as in patient care. Many SPECT-labeled imaging probes that have highly specific distributions with very little background are being used to measure a wide range of biological parameters of importance in small animals including substrate metabolism, blood flow, hypoxia, protein synthesis and receptor characteristics. The utility of this important modality has been significantly enhanced in recent years by the development of methods to image transgene expression in vivo. Furthermore, SPECT is capable of dual-isotope imaging for correlating two biological processes with a single imaging study. Recent demand for small animal SPECT has also been driven by the pharmaceutical industry where in vivo quantification of biological processes to measure an agent's mechanism of action and its concentration at the site of action is necessary. Each of these applications requires excellent spatial resolution, not only because of the small scale of the details to be imaged but also for the demanding detection and estimation tasks. Unfortunately, existing SPECT instrumentation does not provide the required performance, so the development of a high-resolution detector is essential for the improvement of future SPECT systems. To address these issues, we propose to develop a novel detector based on a unique design of a scintillator coupled to a very high spatial resolution readout. Specifically, the scintillator design and fabrication will minimize the loss of resolution arising from parallax errors due to depth-of-interaction effects within the scintillator, while maintaining very high efficiency for the detection of incident radiation. This combination of scintillator and readout, when coupled to a custom designed collimator, will form a SPECT detector module that can achieve extremely fine spatial resolution and high sensitivity in a cost-effective manner. The effort subsequent to the successful development of the detector module will focus on the development of a complete small-animal SPECT system as a prototype product.